With the advancement of science and technology, various electronic products have become indispensable tools in modern people's life. These electronic products can not only assist users in performing various complicated operations, but also provide users with a variety of entertainment functions, such as watching movies, listening to music or enjoying Internet voice communication services. Furthermore, in order to provide commuters or users who are outside some audio/video (AV) entertainments, portable electronic products with AV functions have also been developed, such as mobile phones with music playing functions or walkmans capable of outputting movies to other display devices. Driven by market needs, mobile phone manufacturers have researched and developed mobile phones with music playing functions that are capable of outputting movies to other display devices.
Video output signals of images, audio output signals of voices and audio input signals of microphones have different transmission directions, and their attributes are not all the same. Hence, it usually takes two different types connectors for a single electronic product to provide all the functions of outputting images and voice signals and inputting microphone signals, wherein the two connectors connect with a plug for outputting video image signals and another plug for outputting/inputting voice/microphone audio signals respectively.
More specifically, to enable a mobile phone to output video image signals and output/input voice/microphone audio signals, manufacturers typically use a TV-OUT connector for connection with a display device, so that video image signals can be outputted to the display device via the TV-OUT connector. On the other hand, the manufacturers may adopt a 3.5 mm/2.5 mm audio connector for connection with an earphone or an earphone with a microphone function, so that audio output signals can be outputted to the earphone or microphone audio input signals can be inputted to the mobile phone via the 3.5 mm/2.5 mm audio connector.
However, if video image output signals, audio output signals and microphone audio input signals are transmitted in a mobile phone by the aforesaid manner, the user must bring multiple kinds of connection lines, which causes a considerable inconvenience to the user. Meanwhile, as mobile phones continuously become more compact, fabricating two connectors in a single mobile phone would occupy a certain space and consequently decrease the available space for other electronic components, thus imposing more specification limitations. In view of the above shortcomings and facts, it is important to provide diversified signal transmission modes in an electronic product with the AV entertainment functions, while maintaining the compact size of the electronic product without additional limitations.